/euh nas"pid/ , n. Paleontol.
any member of an extinct order, Anaspida, of small, freshwater jawless fishes of the Silurian and Devonian periods, characterized by a single nostril, narrow rows of scales, and, usually, an armor-plated head.
[ Anaspida name of the order, equiv. to an- AN- 3 + Gk aspid- (s. of aspís shield) + -a neut. pl. n. ending ]